Google for a cheap to make dunking volume cleaner called Ed's Red. It's near perfect for the idea of dunk or flush cleaning since it's not an aerosol and it's cheap to make the sort of volume you'll want and even the used product is re-useable for quite a while. A small plastic squirt bottle is good for sucking it up out of the jar or other container and squirting into the action.
Wear disposable nitrile, not latex, gloves while doing so and work outdoors. Flush then work the action to work the mix into and out of the contact points fully. Repeat flushing and working the parts that move until it's cleaned to your satisfaction. It does the job nicely and when drained out and dried it leaves a light film of the oil behind for both corrosion protection as well as light duty lubrication. You'll still want to put some good gun oil on the more important spots but the ATF will do nicey for most of the lighter duty lubrication duties.